Using data from the Child Health and Development Study (CHDS) birth cohort at the Oakland Kaiser Foundation, it was found that, out of nearly 20,000 individuals born to mothers participating in the Kaiser health plan between 1959 and 1966, almost 12,000 continued to participate in the program until at least age 30. Of these, 186 individuals had been hospitalized within the Kaiser system with sufficient information in their charts to make a potential diagnosis of schizophrenia. Further chart review indicated that there was sufficient evidence of schizophrenia in 122 cases to attempt interviews. Face-to- face diagnostic interviews have been conducted with 100 patients. Initial review of these charts suggests 400 possible cases of schizophrenia. It was found that maternal nutritional status prior to pregnancy, as measured by pre-pregnancy body mass index (PPBMI) was associated with a significantly increased risk of schizophrenia and other schizophrenia spectrum disorders (SSD) in adult offspring. Women who had greater than average PPBMI (> 27) gave birth to infants whose risk of developing schizophrenia or SSD was more than twice that of infants born to women who had low or average PPBMI (< 27). The association was independent of the possible confounding effects of other maternal characteristics, including maternal age, race, education, parity, and cigarette smoking. The relationship of PPBMI to schizophrenia/SSD was not explained by the gender or birthweight of the offspring, nor was the finding limited to schizophrenia/SSD cases with early age at first treatment. The importance of the association between high PPBMI and schizophrenia/SSD is twofold. First, the magnitude of the estimated relative risk is large. Second, and perhaps more important, the percent of pregnancies associated with high PPBMI in the United States has significantly increased since the 1960s. - schizophrenia, prenatal factors - Human Subjects & Human Subjects: Interview, Questionaires, or Surveys Only